Find the number of photons emitted per second by a $25 \text{ W}$ source of monochromatic light of wavelength $6600 \text{ Å}$. What is the photoelectric current assuming $3 \%$ efficiency for the photoelectric effect?

The book “Physics of Physics” was written by

If $m$ is the mass of an electron and $c$ is the speed of light,then the ratio of the wavelength of a photon of energy $E$ to the wavelength of an electron of the same energy is:

What phenomena of light can be explained on the basis of particle theory and wave theory of light?

Photoelectric effect experiments are performed using three different metal plates $p, q$ and $r$ having work functions $\phi_p=2.0 \ eV, \phi_q=2.5 \ eV$ and $\phi_r=3.0 \ eV$,respectively. $A$ light beam containing wavelengths of $550 \ nm, 450 \ nm$ and $350 \ nm$ with equal intensities illuminates each of the plates. The correct $I-V$ graph for the experiment is:

The spectrum of an oil flame is an example of: